| From 76a4d5cfccd66e060835878cd71c375d210d7ca0 Mon Sep 17 00:00:00 2001 |
| From: Sasha Levin <sashal@kernel.org> |
| Date: Thu, 3 Jun 2021 00:01:12 +0000 |
| Subject: PCI/sysfs: Fix dsm_label_utf16s_to_utf8s() buffer overrun |
| MIME-Version: 1.0 |
| Content-Type: text/plain; charset=UTF-8 |
| Content-Transfer-Encoding: 8bit |
| |
| From: Krzysztof Wilczyński <kw@linux.com> |
| |
| [ Upstream commit bdcdaa13ad96f1a530711c29e6d4b8311eff767c ] |
| |
| "utf16s_to_utf8s(..., buf, PAGE_SIZE)" puts up to PAGE_SIZE bytes into |
| "buf" and returns the number of bytes it actually put there. If it wrote |
| PAGE_SIZE bytes, the newline added by dsm_label_utf16s_to_utf8s() would |
| overrun "buf". |
| |
| Reduce the size available for utf16s_to_utf8s() to use so there is always |
| space for the newline. |
| |
| [bhelgaas: reorder patch in series, commit log] |
| Fixes: 6058989bad05 ("PCI: Export ACPI _DSM provided firmware instance number and string name to sysfs") |
| Link: https://lore.kernel.org/r/20210603000112.703037-7-kw@linux.com |
| Reported-by: Joe Perches <joe@perches.com> |
| Signed-off-by: Krzysztof Wilczyński <kw@linux.com> |
| Signed-off-by: Bjorn Helgaas <bhelgaas@google.com> |
| Signed-off-by: Sasha Levin <sashal@kernel.org> |
| --- |
| drivers/pci/pci-label.c | 2 +- |
| 1 file changed, 1 insertion(+), 1 deletion(-) |
| |
| diff --git a/drivers/pci/pci-label.c b/drivers/pci/pci-label.c |
| index 781e45cf60d1..cd84cf52a92e 100644 |
| --- a/drivers/pci/pci-label.c |
| +++ b/drivers/pci/pci-label.c |
| @@ -162,7 +162,7 @@ static void dsm_label_utf16s_to_utf8s(union acpi_object *obj, char *buf) |
| len = utf16s_to_utf8s((const wchar_t *)obj->buffer.pointer, |
| obj->buffer.length, |
| UTF16_LITTLE_ENDIAN, |
| - buf, PAGE_SIZE); |
| + buf, PAGE_SIZE - 1); |
| buf[len] = '\n'; |
| } |
| |
| -- |
| 2.30.2 |
| |
